At a press conference, the Labour leader brandished over 400 pages of unredacted minutes from meetings between UK and US government officials.

He hailed the spool of documents as proof the Prime Minister had put the health service on the table in a post-Brexit free trade agreement.

But he was met with a rigorous rebuff from the Conservatives, whose International Trade Secretary Liz Truss said: ‘The NHS will not be on the table in any future trade deal and the price that the NHS pays for drugs will not be on the table.

‘This sort of conspiracy theory fuelled nonsense is not befitting of the leader of a major political party.’

The roundtable meetings outlined in the papers took place during Ms May’s premiership between July 2017 and July 2018.

Mr Johnson has since overhauled the cabinet, replacing the ministers and vowing to never involve the NHS in a bargain with Washington.

Yet as election campaigning was ramped up, Mr Corbyn used the previously ‘secret document’ – which only mentions the NHS a handful of times – to tear into the Conservatives for putting Britain’s healthcare at risk.

Except it was not so secret, as it was revealed after the press conference that the documents had been uploaded to online sharing platform Reddit at the end of October.

At a press conference, the Labour leader brandished over 400 pages of unredacted minutes from meetings between UK and US government officials

In a highly-charged statement in Westminster today, the Labour leader said:

‘On behalf of the Conservative government, officials reassured their US counterparts that the US should expect the UK to be a ‘liberalising influence’ and that together they could ‘fly the good flag for services liberalisation’.’

The document said:

‘The US explained that the conversation on services could be positive and the success of a UK-US conversation on services could be an example to other Member States and non EU countries. They could fly the good flag of services liberalisation…

‘The UK explained… it had a very open system already and the US should expect the UK to be a liberalising influence.’

What this means:

At a meeting on July 25 2017, the US team did say that together their country and the UK could promote services liberalisation, however the comment was made in comparison to the liberal trade policy currently enjoyed among EU member states, which does not compromise the NHS.

Mr Corbyn said:

‘The US and the UK have already finished the discussion on lengthening patents for medicines. Longer patents can mean only one thing: more expensive drugs.’

The document said:

‘Patent law is largely delivered by the European Patent Office, which is unaffected by Brexit.’

What this means:

The document suggests that the UK’s current patent regulation will not change post-Brexit as it is regulated by a non-EU body.

Mr Corbyn said:

‘Labour has been warning that NHS services will also be on the table in trade talks for a sellout deal with Trump… the documents show Trump was right.

‘These documents make clear that for the US – to quote page 41 of the third meeting report – ‘everything is included unless something is specifically excluded’.

‘They want ‘total market access as the baseline assumption of a trade negotiation’.’

The document said:

‘The US thinks the NCM (non-conforming measures) approach incentivises freer trade, because the assumption is that everything is included unless something is explicitly excluded…

The US want to go into trade negotiations with the negative list approach, meaning that items are taken off the table, rather than starting from scratch and adding different elements.

But that does nothing to prevent the UK ruling out including a particular sector in a deal, such as healthcare.

Labour’s Barry Gardiner said:

‘One of the things that undermines our NHS in trade talks is a negative list system.’

The document said:

‘The US explained the negative list approach was very important to the US… He asked what the UK’s current thinking was on approach.

‘The UK explained that it was too early for that specific conversation.’

What this means:

No cast-iron guarantees have been made to adopt a negative list system in future trade talks, with the UK team of the mindset that these are only preliminary talks.

Negative lists are the bottom-up process of ruling out sectors and industries that are on the table.

Mr Corbyn said:

‘Have a look on page 42 and 43, where the US even agrees to share its public lines to help our government with its media narrative.’

The document said:

‘UK to discuss internally with central US team regarding joint press statement and launch of JES on publication.’

What this means:

A November 2018 meeting where both parties discussed economic analysis – with no mention of the NHS of pharmaceuticals – ended with an agreement to set up a joint press statement when the Joint Economic Study was published.

Mr Corbyn said:

‘You may want to look at how Trump’s America absolutely refuses to mention climate change in the deal, see the second meeting on page 17.’

The document said:

‘The US responded emphatically that climate change is the most political sensitive question for the US…

‘US stated this ban (on mentioning climate change in trade deals) would not be lifted any time soon.’

What this means:

A UK delegate asked if environmental action could be weaved into a future trade deal, but this was effectively stonewalled by the US.

Mr Corbyn said:

‘We have now got evidence that under Boris Johnson the NHS is on the table and will be up for sale.’

The document said:

‘Nursing was the other profession that the US was interested in… The US were interested to know if it would be really problematic for the UK to act in this area – they were sensitive to the particular sensitivities with the health sector in the UK.’

What this means:

The government insists this passage demonstrates that the US already knows the UK will not accept unfettered access to the NHS.